* use Mat class for Shape description

* shape specialization constant in compute shader

* wip

* wip

* test forward_inplace, add binaryop unaryop sigmoid test

* fix arm unaryop test

* fix arm binaryop test

* make shape hint optional, cast int8 to fp32, add cast test

* wip

* follow the good and old local size setting for conv1x1

* the optimal local size rewrite

* fix build on msvc

* add permute shader for all packing layout, add permute test

* concat and slice patial shape constant, slice test

* fix slice test

* interp test

* add lrn test, test packing layout implicitly

* add eltwise test

* add normalize test

* add instancenorm test

* reorg shape constant

* simple local group size partition

* add shape constant param

* Change DataReader::read()'s signature to fix warning C4267

This CL fixes lots of warning "C4267: 'initializing': conversion from
'size_t' to 'int'" in our codebase by matching DataReader::read()'s
signature to fread().

* Fix warnings C4244 and C4267 in tools/ncnnoptimize.cpp

C4244: 'initializing': conversion from 'double' to 'float',
    possible loss of data
C4267: 'initializing': conversion from 'size_t' to 'int',
    possible loss of data

* Fix warning C4244 in src\layer\selu.cpp

C4244: '=': conversion from 'double' to 'float', possible loss of data

* Fix warning C4244 in src\layer\cast.cpp

C4244: '=': conversion from 'double' to 'float', possible loss of data
C4244: 'return': conversion from 'float' to 'signed char', possible loss of data

* Fix warning C4244 in src\layer\psroipooling.cpp

C4244: 'initializing': conversion from 'double' to 'float',
    possible loss of data
C4244: 'initializing': conversion from 'double' to 'int',
    possible loss of data